#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <queue>
#include <deque>
#include <set>
#include <map> 
#include <unordered_set>

#define flr(x, l, r) for (int x = l; x <= r; ++x)
#define frl(x, r, l) for (int x = r; x >= l; --x)
#define fmp(x, t) for (int x = h[t]; ~x; x = ne[x])
#define LL long long
#define mt memset
#define my memcpy
#define szf sizeof
#define INF 0x3f3f3f3f
#define in(x) scanf("%d", &x)
#define out(x) printf("%d", x)
#define inll(x) scanf("%lld", &x)
#define outll(x) printf("%lld", x)
#define pn printf("\n")
#define con continue
#define bk break
#define vc vector
#define pb push_back
#define sz size
#define PII pair<int, int>
#define x first
#define y second
#define P_q priority_queue
#define ft front
#define pf push_front
#define popf pop_front
#define it insert
#define ct count

using namespace std;

const int N = 10010, M = 30010;

int n, m;
int h[N], e[M], ne[M], idx;
int dfn[N], low[N], timestamp;
int root, ans;

void add(int a, int b) {
    e[idx] = b, ne[idx] = h[a], h[a] = idx ++ ;
}

void tarjan(int u) {
    dfn[u] = low[u] = ++ timestamp;
    
    int cnt = 0;
    fmp (i, u) {
        int j = e[i];
        if (!dfn[j]) {
            tarjan(j);
            low[u] = min(low[u], low[j]);
            if (low[j] >= dfn[u]) cnt ++ ;
        }
        else low[u] = min(low[u], dfn[j]);
    }
    
    if (u != root) cnt ++ ;
    
    ans = max(ans, cnt);
}

int main() {
	while (scanf("%d%d", &n, &m), n || m) {
	    mt(dfn, 0, szf dfn), mt(h, -1, szf h);
	    idx = timestamp = 0;
	    
	    while (m -- ) {
	        int a, b;
	        in(a), in(b);
	        add(a, b), add(b, a);
	    }
	    
	    ans = 0;
	    int cnt = 0;
	    for (root = 0; root < n; ++ root)
	        if (!dfn[root]) {
	            cnt ++ ;
	            tarjan(root);
	        }
	        
	    out(ans + cnt - 1), pn;
	}
	
    return 0;
}